Adaptive beamforming configuration methods and apparatus for wireless access points serving as handoff indication mechanisms in wireless local area networks

ABSTRACT

In one illustrative example, a technique for use in operating a wireless access point (AP) for serving as a handoff indication mechanism in a first wireless network is described. The handoff indication mechanism is configured to communicate handoff indications in response to mobile devices leaving coverage of the first wireless network, via an RF coverage region of the AP, for mobile device handoff to a second wireless network. The AP is provided in an ingress or egress region of the first wireless network, where it receives RF signals from one or more communication devices and determines and sets wireless transceiver parameters for adjusting boundaries of its RF coverage region. The AP also operates with the adjusted RF coverage region to serve as part of the handoff indication mechanism in the first wireless network, so that the handoff indications are communicated in response to the mobile devices leaving coverage of the first wireless network, via the adjusted RF coverage region, for mobile device handoff to the second wireless network.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims priority to U.S.non-provisional patent application having application Ser. No.12/700,118 and filing date of 4 Feb. 2010, now U.S. Pat. No. 7,936,724B2, which is a continuation of and claims priority to U.S.non-provisional patent application having application Ser. No.11/743,741 and filing date of 3 May 2007, now U.S. Pat. No. 7,684,370B2, each application being hereby incorporated by reference herein.

BACKGROUND

1. Field of the Technology

The present disclosure relates generally to wireless access points (APs)in wireless local area networks (WLANs), and more particularly toadaptive beamforming configuration methods and apparatus for wirelessAPs which serve as tripwires in WLANs.

2. Description of the Related Art

A mobile communication device may be designed to operate on twodifferent types of heterogeneous wireless networks, such as a wirelesslocal area network (WLAN) (e.g. IEEE 802.11 based wireless network) anda wireless wide area network (WWAN) (e.g. a cellular telecommunicationsnetwork). With these types of mobile communication devices, it isconvenient to have advance notice of when the mobile device will behanded-off from the WLAN to the WWAN, so that voice communicationsessions of the mobile device may be seamlessly maintained during thehandoff. For example, if the mobile device and/or network may be madeaware in advance that the mobile device is about to leave the WLAN, aconnection may be established between the mobile device and the WWANbefore the connection with the WLAN is lost. For this reason, a wirelessaccess point (AP) may be deployed specifically to cover regions ofingress and/or egress of the WLAN and serve as a “tripwire” to providesuch advance handoff notice. If such AP tripwires had suitable coverageregions that could be easily configured, the reliability and timelinessof handoffs may be enhanced.

Accordingly, what are needed are methods and apparatus to improvehandoffs for mobile devices as described.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure will now be described, by way ofexample only, with reference to the attached figures. Same referencenumerals are used in different figures to denote similar elements.

FIG. 1 is a block diagram which illustrates a communication system whichincludes a plurality of mobile communication devices and one or morewireless communication networks (e.g. WLANs);

FIG. 2 is a more detailed schematic diagram of the mobile communicationdevices of FIG. 1, namely, a mobile station of the preferred embodiment;

FIG. 3 is a schematic block diagram of basic components of a wirelessaccess point which may serve as a handoff indication mechanism in theWLAN;

FIG. 4 is a schematic diagram of wireless transceiver components of thewireless access point of FIG. 3 which are adapted to perform an adaptivebeamforming technique for configuration of the wireless access point;

FIG. 5 is a flowchart for describing a method for use in configuring thewireless access point for use as the handoff indication mechanism in theWLAN;

FIG. 6 is the first in a series of four illustrations of FIGS. 6-9 ofthe WLAN of the present disclosure, where a wireless access point thatwill serve as the handoff indication mechanism in the WLAN is shownlocated in a WLAN ingress/egress region;

FIG. 7 is a second illustration of the WLAN of FIG. 6 where, during aconfiguration procedure of the wireless access point, a first group ofcommunication devices are positioned at locations of undesired RFcoverage of the AP tripwire, outside of an RF coverage boundary of aWLAN coverage region and a second group of communication devices arepositioned at locations of desired RF coverage of the AP tripwire,around the RF coverage boundary of the WLAN coverage region;

FIG. 8 is a third illustration of the WLAN where, during theconfiguration procedure of the wireless access point, boundaries of itsRF coverage region are adjusted and set such that RF signal coverage ofthe first group of communication devices is minimized but RF signalcoverage of the second group of communication devices is maximized; and

FIG. 9 is the fourth and final illustration of the WLAN where theboundaries of the RF coverage region of the wireless access point areset for use as a handoff indication mechanism in the WLAN.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Methods and apparatus for use in configuring a wireless access point(AP) which serves as a handoff indication mechanism (“AP tripwire”) in awireless local area network (WLAN) for mobile device handoffs betweenthe WLAN and a wireless wide area network (WWAN) are described. During aconfiguration procedure or “training mode” of operation for the wirelessAP, radio frequency (RF) signals transmitted from a plurality ofcommunication devices are received by the wireless AP. The plurality ofcommunication devices include a first group of communication devicespositioned at locations of undesired RF coverage of the AP tripwire,outside of an RF coverage boundary of a WLAN coverage region of one ormore other wireless APs of the WLAN, as well as a second group ofcommunication devices positioned at locations of desired RF coverage ofthe AP tripwire, around the RF coverage boundary of the WLAN coverageregion. Based on the received RF signals, wireless transceiverparameters of the wireless AP are automatically determined and set toadjust boundaries of an RF coverage region, such that RF signal coverageof the first group of communication devices is minimized but RF signalcoverage of the second group of communication devices is maximized.Preferably, the wireless transceiver parameters are determined throughuse of an adaptive beamforming technique (e.g. a “minimaxoptimization”), which is performed automatically by the wireless APduring the configuration procedure without user intervention. After theconfiguration procedure, the wireless AP operates with use of theconfigured wireless transceiver parameters in a normal, steady-statemode of operation as the AP tripwire of the WLAN. Advantageously, the RFsignal coverage of the AP tripwire is appropriately adjusted and set soas to help provide reliable and timely mobile device handoffs betweenthe WLAN and the WWAN.

To illustrate basic network architecture, FIG. 1 is a block diagramwhich illustrates a communication system 100 which includes a publicnetwork 102 (e.g. the Internet) and a private network 104. In thepresent embodiment, private network 104 is or includes a wireless localarea network (WLAN). In the WLAN, terminals may connect to theirassociated networks through access points (APs) as shown. Preferably, atleast some of the APs are wireless APs of the WLAN and at least some ofthe terminals are mobile/wireless communication devices which interfaceand connect through these wireless APs. Such terminals and APs mayoperate in accordance with well-known IEEE 802.11 standards. Theterminals shown in public network 102 include terminals 110 and 112which have interfaced with AP 106, and terminals 114, 116, and 118 whichhave interfaced with AP 108. The terminals shown in private network 104include terminals 134, 136, 138 which have interfaced with AP 132, andterminals 144 and 146 which have interfaced with AP 142.

Private network 104 which includes the WLAN provides various data andcommunication services to its terminals. For example, private network104 may provide for voice telephony communication services for itsterminals with use of Voice over IP (VoIP) communications. For thesetypes of services, private network 104 may utilize a VoIP serverarchitecture for VoIP communication sessions, and/or an e-mail serverarchitecture for e-mail message communications, as examples. For thesepurposes, communication system 100 may also include at least one VoIP orSession Initiation Protocol (SIP) proxy server. In the presentembodiment, communication system 100 has a VoIP or SIP proxy server 121in public network 102 and a VoIP or SIP proxy server 130 in privatenetwork 104. Note that some communication applications utilized byterminals, such VoIP applications, require the use of SIP. SIP iswell-documented in standard documents such as Request For Comments (RFC)3261. A firewall 124 may also be provided in private is network 104 forpreventing unauthorized access from users in public network 102.

Outside of the networks 102 and 104 is a wireless wide area network(WWAN) 195 which may be a cellular telecommunication network whichincludes a plurality of base stations. At least some of the terminals ofFIG. 1 are adapted to operate in both the WLAN and the WWAN. Asapparent, the illustrative example of the present disclosure is directedto WLANs of the IEEE 802.11 network type and WWANs of the cellularnetwork type. Note, however, that the WLAN and WWANs may be any suitableheterogeneous networks. For example, one of the networks may be a WiMAX(e.g. 802.16-based) network. If the WLAN is a WiMAX network, forexample, then the WWAN may be a cellular telecommunications network.Also for example, if the WWAN is a WiMAX network, then the WLAN may bean IEEE 802.11-based network. Other variations are possible as well.

Referring now to FIG. 2, electrical components of a typical mobileterminal 138 (e.g. a mobile communication device or mobile station) willbe described. Terminal 138 is adapted to operate in connection with thewireless APs of communication system 100 of FIG. 1 (e.g. a WLAN 190 ofFIG. 2) as well as a WWAN (e.g. a cellular telecommunications network).Terminal 138 is preferably a two-way mobile communication device havingat least voice and advanced data communication capabilities, includingthe capability to communicate with other computer systems. Depending onthe functionality provided by terminal 138, it may be referred to as adata messaging device, a two-way pager, a cellular telephone with datamessaging capabilities, a wireless Internet appliance, or a datacommunication device (with or without telephony capabilities).

As described, terminal 138 is adapted to wirelessly communicate withWLAN 190. Also as shown, terminal 138 may be adapted to wirelesslycommunicate with cellular base station transceiver systems 200. Forcommunication with cellular networks, terminal 138 utilizescommunication subsystem 211. For communication with WLANs, terminal 138utilizes an additional communication subsystem 291 which has the same orsimilar structural components as communication subsystem 211. With suchconfiguration, terminal 138 may be referred to as a “dual mode” mobilestation. Although shown in FIG. 2 as having separate and independentsubsystems, at least some portions or components of these otherwisedifferent subsystems may be shared where possible.

Communication subsystem 211 includes a receiver 212, a transmitter 214,and associated components, such as one or more (preferably embedded orinternal) antenna elements 216 and 218, local oscillators (LOs) 213, anda processing module such as a digital signal processor (DSP) 220.Communication subsystem 211 is analogous to RF transceiver circuitry 108a and antenna 110 a shown in FIG. 1. As will be apparent to thoseskilled in field of communications, particular design of communicationsubsystem 211 depends on the communication network in which terminal 138is intended to operate.

Terminal 138 may send and receive communication signals through thenetwork after required network procedures have been completed. Signalsreceived by antenna 216 through the network are input to receiver 212,which may perform such common receiver functions as signalamplification, frequency down conversion, filtering, channel selection,and like, and in example shown in FIG. 2, analog-to-digital (A/D)conversion. A/D conversion of a received signal allows more complexcommunication functions such as demodulation and decoding to beperformed in DSP 220. In a similar manner, signals to be transmitted areprocessed, including modulation and encoding, for example, by DSP 220.These DSP-processed signals are input to transmitter 214 fordigital-to-analog (D/A) conversion, frequency up conversion, filtering,amplification and transmission over communication network via antenna218. DSP 220 not only processes communication signals, but also providesfor receiver and transmitter control. For example, the gains applied tocommunication signals in receiver 212 and transmitter 214 may beadaptively controlled through automatic gain control algorithmsimplemented in DSP 220.

Network access is associated with a subscriber or user of terminal 138,and therefore terminal 138 requires a memory module 262, such as aSubscriber Identity Module or “SIM” card, a Universal SIM (U-SIM), or aRemovable User Identity Module (R-UIM), to be inserted in or connectedto an interface 264 of terminal 138 in order to operate in the network.Since terminal 138 is a mobile battery-powered device, it also includesa battery interface 254 for receiving one or more rechargeable batteries256. Such a battery 256 provides electrical power to most if not allelectrical circuitry in terminal 138, and battery interface 254 providesfor a mechanical and electrical connection for it. Battery interface 254is coupled to a regulator (not shown in FIG. 2) that provides aregulated voltage V+ to all of the circuitry.

Terminal 138 includes a microprocessor 238 that controls overalloperation of terminal 138. Communication functions, including at leastdata and voice communications, are performed through communicationsubsystem 211. Microprocessor 238 also interacts with additional devicesubsystems such as a display 222, a flash memory 224, a random accessmemory (RAM) 226, auxiliary input/output (I/O) subsystems 228, a serialport 230, a keyboard 232, a speaker 234, a microphone 236, a short-rangecommunications subsystem 240, and any other device subsystems generallydesignated at 242. Some of the subsystems shown in FIG. 2 perform incommunication-related functions, whereas other subsystems may provide“resident” or on-device functions. Notably, some subsystems, such askeyboard 232 and display 222, for example, may be used for bothcommunication-related functions, such as entering a text message fortransmission over a communication network, and device-resident functionssuch as a calculator or task list. Operating system software used bymicroprocessor 238 is preferably stored in a persistent store such asflash memory 224, which may alternatively be a read-only memory (ROM) orsimilar storage element (not shown). Those skilled in the art willappreciate that the operating system, specific device applications, orparts thereof, may be temporarily loaded into a volatile store such asRAM 226.

Microprocessor 238, in addition to its operating system functions,preferably enables execution of software applications on terminal 138. Apredetermined set of applications that control basic device operations,including at least data and voice communication applications, willnormally be installed on terminal 138 during its manufacture. Apreferred application that may be loaded onto terminal 138 may be apersonal information manager (PIM) application having the ability toorganize and manage data items relating to user such as, but not limitedto, e-mail, calendar events, voice mails, appointments, and task items.Naturally, one or more memory stores are available on terminal 138 andSIM 256 to facilitate storage of PIM data items and other information.

The PIM application preferably has the ability to send and receive dataitems via the wireless network. In a preferred embodiment, PIM dataitems are seamlessly integrated, synchronized, and updated via thewireless network, with the wireless device user's corresponding dataitems stored and/or associated with a host computer system therebycreating a mirrored host computer on terminal 138 with respect to suchitems. This is especially advantageous where the host computer system isthe wireless device user's office computer system. Additionalapplications may also be loaded onto terminal 138 through network, anauxiliary I/O subsystem 228, serial port 230, short-range communicationssubsystem 240, or any other suitable subsystem 242, and installed by auser in RAM 226 or preferably a non-volatile store (not shown) forexecution by microprocessor 238. Such flexibility in applicationinstallation increases the functionality of terminal 138 and may provideenhanced on-device functions, communication-related functions, or both.For example, secure communication applications may enable electroniccommerce functions and other such financial transactions to be performedusing terminal 138.

In a data communication mode, a received signal such as a text message,an e-mail message, or web page download will be processed bycommunication subsystem 211 and input to microprocessor 238.Microprocessor 238 will preferably further process the signal for outputto display 222 or alternatively to auxiliary I/O device 228. A user ofterminal 138 may also compose data items, such as e-mail messages, forexample, using keyboard 232 in conjunction with display 222 and possiblyauxiliary I/O device 228. Keyboard 232 is preferably a completealphanumeric keyboard and/or telephone-type keypad. These composed itemsmay be transmitted over a communication network through communicationsubsystem 211.

For voice communications, the overall operation of terminal 138 issubstantially similar, except that the received signals would be outputto speaker 234 and signals for transmission would be generated bymicrophone 236. Alternative voice or audio I/O subsystems, such as avoice message recording subsystem, may also be implemented on terminal138. Although voice or audio signal output is preferably accomplishedprimarily through speaker 234, display 222 may also be used to providean indication of the identity of a calling party, duration of a voicecall, or other voice call related information, as some examples.

Serial port 230 in FIG. 2 is normally implemented in a personal digitalassistant (PDA)-type communication device for which synchronization witha user's desktop computer is a desirable, albeit optional, component.Serial port 230 enables a user to set preferences through an externaldevice or software application and extends the capabilities of terminal138 by providing for information or software downloads to terminal 138other than through a wireless communication network. The alternatedownload path may, for example, be used to load an encryption key ontoterminal 138 through a direct and thus reliable and trusted connectionto thereby provide secure device communication. Short-rangecommunications subsystem 240 of FIG. 2 is an additional optionalcomponent that provides for communication between terminal 138 anddifferent systems or devices, which need not necessarily be similardevices. For example, subsystem 240 may include an infrared device andassociated circuits and components, or a Bluetooth™ communication moduleto provide for communication with similarly enabled systems and devices.Bluetooth™ is a registered trademark of Bluetooth SIG, Inc.

FIG. 3 is a schematic block diagram of basic components of a wirelessaccess point (AP) 300 which serves as a handoff indication mechanism orAP tripwire in a wireless local area network (WLAN). Wireless AP 300 isadapted to engage in a configuration procedure in a “training mode” ofoperation with use of an adaptive beamforming technique, which isexecuted prior to its use as a handoff indication mechanism.

As shown in FIG. 3, wireless AP 300 includes a processor 302 (e.g. amicroprocessor, microcontroller, and/or digital signal processor),memory 310 coupled to processor 302, a wireless transceiver array 304coupled to processor 302, an antenna array 306 coupled to wirelesstransceiver array 304, a user interface 312 coupled to processor 302,and a power source interface 314. Although only one processor 302 isshown in FIG. 3, processor 302 may be embodied as two or more processors(e.g. microprocessor and DSP) and wireless transceiver array 304 may beembodied as two or more wireless transceiver portions. Power sourceinterface 314 supplies power to all electrical components of wireless AP300 by interfacing with a power source (e.g. AC power, battery, and/orsolar power). A network communication interface 320 is coupled toprocessor 302 and provided for interfacing wireless AP 300 with theWLAN. Network interface 302 may be a wired communication interface, suchas an Ethernet communication interface.

Processor 302 of wireless AP 300 includes an adaptive beamformingprocess 314 (e.g. a minimax optimization process) which helps determinetransceiver parameters 316 for wireless transceiver array 304 during theconfiguration procedure. Such transceiver parameters 316 are set andstored in memory 310 for subsequent use during normal steady-stateoperation of wireless AP 300 as the handoff indication mechanism or APtripwire. Adaptive beamforming process 314 may be embodied as computerinstructions which are executable by processor 302. Transceiverparameters 316 are used by wireless AP 300 to establish its RF coverageregion while serving as the handoff indication mechanism in the WLAN. Ifnecessary (e.g. in a wideband environment such as an OFDM systems), aset of transceiver parameters 316 may be stored for each frequency orfrequency pair associated with all of the usable frequency channels ofthe relevant RF band for RF communications. The basic components ofwireless AP 300 of FIG. 3 may be particularly utilized as will bedescribed later in relation to FIGS. 5-9. User interface 312, which maybe or include user actuable switches or keys (e.g. directly on a housingof wireless AP 300 or through a computer terminal (e.g. PC) connected towireless AP 300), for example, may be utilized to initiate theconfiguration procedure and adaptive beamforming process 314. That is,the configuration procedure/adaptive beamforming technique of wirelessAP 300 may be initiated in response to a user interface signal from userinterface 312, but thereafter adaptive beamforming process 314 operatesautomatically to determine transceiver parameters 316 for wireless AP300 without further user intervention.

Showing more exemplary detail, FIG. 4 is a schematic diagram of wirelesstransceiver components 400 of the wireless AP which are adapted toperform an adaptive beamforming technique for configuration of thewireless AP. In the example of FIG. 4, the receiver portion is shown butthe transmitter portion may utilize a similar approach. In FIG. 4,wireless transceiver components 400 include an antenna array having aplurality of antennas, where each antenna is coupled to a separatecorresponding RF front end component. A frequency synthesizer, whichreceives a fixed oscillator frequency signal from an oscillator (“NCO”),is coupled to each RF front end component. Each RF front end componenthas an output coupled to an input of an analog-to-digital converter(A/D), which has an output coupled to signal demodulators (which includesignal mixers) and subsequent low pass filters. Outputs from the lowpass filters are coupled to inputs of a digital signal processor (DSP).The controller serves to control the adaptive beamforming process forproducing transceiver parameters in the configuration procedure for theDSP.

Note that there are many different types of adaptive beamformingalgorithms, conventional or otherwise, which may be utilized within thewireless AP to obtain the desired result. In a preferred embodiment, aminimax optimization technique is performed in the configurationprocedure. Using a minimax optimization technique, RF signals areminimized for those communication devices outside of the desired RFcoverage region and maximized for those communication devices within thedesired RF coverage region. In the present techniques, each RF signal ismultiplied with complex weights that adjust a magnitude and a phase ofthe RF signal to and from each antenna in the antenna array. This causesthe output of from the antenna array to form a transmit/receive beam inthe desired direction, while minimizing the output in other directions.The application of complex weights to the RF signals from differentantennas of the antenna array involves complex multiplications that maymap onto embedded DSP blocks of the DSP.

Referring now ahead to FIG. 6, what is shown is the first in a series offour illustrations of FIGS. 6-9 of a WLAN 600 which utilizes techniquesof the present disclosure. WLAN 600 has a plurality of wireless accesspoints (APs) 602 which together provide a local radio frequency (RF)coverage region for WLAN 600. For example, as part of this local RFcoverage region of WLAN 600, a wireless AP 606 provides an RF coverageregion 608 and a wireless AP 610 provides an RF coverage region 612.When within the local RF coverage region of WLAN 600, mobilecommunication devices are provided with wireless communications and mayaccess communication services within it. Outside of the RF coverageregion of WLAN 600, mobile devices cannot communicate through or accessservices of WLAN 600. WLAN 600 and its mobile devices may operateaccording to IEEE 802.11-based communication standards.

A wireless wide area network (WWAN) such as a cellulartelecommunications network may also be available to providecommunication services for mobile devices, even when the mobile devicesare outside of the local RF coverage area of WLAN 600. In FIG. 6, one RFcoverage region 604 of a WWAN within which mobile devices maycommunicate is shown. As depicted, RF coverage region 604 of the WWANoverlaps with at least part of the local RF coverage region of WLAN 600.Examples of the WWAN as a digital cellular telecommunications networkoperating in accordance with a cellular telecommunication standardinclude a Global Systems for Mobile Communications (GSM) and GeneralPacket Radio Service (GPRS) network, a Code Division Multiple Access(CDMA) network, or the International Mobile Telecommunications (IMT)family of Enhanced Data Rates for GSM Evolution (EDGE), Universal MobileTelecommunication System (UMTS), or CDMA2000 network.

The mobile device may initially operate in a voice communication sessionin WLAN 600. If the mobile device is moved outside of the local RFcoverage region of WLAN 600 during the voice communication session, thevoice communication session will need to be “handed off” to the WWAN.Since WLAN 600 and the WWAN are two different heterogeneous wirelessnetworks, this type of handoff may be referred to as a “vertical”handoff. Such vertical handoffs are needed particularly atingress/egress regions of WLAN 600, or predetermined locations at whichmobile devices are known to exit or leave WLAN 600. An ingress/egressregion may be, for example, a region associated with an entrance/exit ofa building within which WLAN 600 operates. In FIG. 6, the ingress/egressregion for mobile devices exists between two dashed lines 650 and 652.If the mobile device is moved from RF coverage area 608 of WLAN 600 pastthe ingress/egress region (i.e. in a direction upwards in the drawing),a voice communication session of the mobile device will need to behanded off to the WWAN in its RF coverage region 604. Note, however,that RF coverage with WLAN 600 may be lost suddenly and undesirablydisrupt the voice communication sessions without mechanisms in thenetwork to assist in this process.

Therefore, a wireless AP 614 is provided in WLAN 600 to serve as ahandoff indication mechanism or an “AP tripwire” in WLAN 600. In FIG. 6,wireless AP 614 has not yet been configured and has an RF coverageregion that is not yet optimized for handoff indication purposes.Wireless AP 614 may utilize the components shown and described earlierin relation to FIGS. 3 and 4 for adaptive beamforming configurationprior to such AP tripwire operation.

For AP tripwire operation, wireless AP 614 is intentionally setup andpositioned in the ingress/egress region of WLAN 600 (e.g. in betweendashed lines 650 and 652). During steady-state operation of wireless AP614 in WLAN 600, wireless AP 614 operates in what is referred to as a“handoff indication” mode of operation. When a mobile device is withinan RF coverage region 616 of wireless AP 614, it is likely that themobile device will be exiting or entering the RF coverage of WLAN 600.If the mobile device is exiting WLAN 600, then it may need to behanded-off to the WWAN in RF coverage area 604. Therefore, when themobile device is within RF coverage region 616, wireless AP 614 causes ahandoff indication to be sent to the mobile device, to WLAN 600, or toboth, in order to assist in providing a more reliable and timelyvertical handoff for the mobile device to the WWAN.

If RF coverage region 616 of wireless AP 614 is not suitably configured(as is shown in FIG. 6), however, then wireless AP 614 may cause thehandoff indication to be sent wrongfully (e.g. false detection) orprematurely. On the other hand, if RF coverage region 616 is unsuitablethen wireless AP 614 may cause the handoff indication to be provided toolate (i.e. after the handoff procedure has been or should have beeninitiated) and not serve the purpose of providing adequate forewarning.For this reason, wireless AP 614 is adapted to operate in aconfiguration mode of operation to suitably configure and adjustboundaries of its RF coverage region 616 so that wireless AP 614 willprovide a reliable and timely handoff indication during steady-stateoperation (i.e. during the handoff indication mode). Preferably, otheradjacent “interior” wireless APs (e.g. wireless APs 606 and 610) aresimilarly adapted to configure and adjust boundaries of their associatedRF coverage regions, so as to fill in “holes” or “gaps” in RF coveragein response to the resulting RF coverage region of wireless AP 614. Thismay be done in order to minimize false handoffs for mobile devices.

FIG. 7 is a second illustration of WLAN 600 where a configurationprocedure is being performed for wireless AP 614. As shown in FIG. 7, aplurality of communication devices are intentionally and strategicallylocated around the ingress/egress region of WLAN 600 in a fixed positionfor the configuration procedure. These communication devices are usedfor the purpose of the configuration procedure, and subsequently removedfor steady-state operation of wireless AP 614. In one approach, thesecommunication devices are mobile devices which have the same or similarstructure and functionality as mobile terminal 138 of FIG. 2 and areoperational for end users as ordinary mobile communication devices. Inanother approach, the communication devices are specially-designedconfiguration devices which are not operational for end users asordinary mobile communication devices. In the present example, thecommunication devices are mobile devices with the same or similarstructure as mobile terminal 138 of FIG. 2.

As shown in FIG. 7, a first group of mobile devices 620, 622, 624, 626,632, and 680 are positioned near the ingress/egress region at locationsoutside of a desired AP tripwire coverage (many of which are shown to bewithin an RF coverage boundary of WLAN 600 formed by RF coverage regions608 and 612). On the other hand, a second group of mobile devices 630,634, 636, 638, and 639 are positioned in the ingress/region at locationsaround and defining the desired AP tripwire coverage (many of which areshown to be along and outside the RF coverage boundary of WLAN 600formed by RF coverage regions 608 and 612). Within the RF coverageboundary of WLAN 600, mobile devices may communicate with WLAN 600;outside of the RF coverage boundary of WLAN 600, mobile devices areunable to communicate with WLAN 600. Note that both the first and thesecond group of mobile devices are also located within RF coverageregion 604 of the WWAN.

Each mobile device in FIG. 7 is associated with a mobile deviceidentifier (e.g. an identification number, a telephone number, an IPaddress, etc.) that is unique to each device. Memory of wireless AP 614may store each such mobile device identifier in association withindications for AP tripwire coverage. For example, each mobile deviceidentifier may be stored in association with either a first indicationcorresponding to the first group of mobile devices that are within theRF coverage boundary of WLAN 600, or a second indication correspondingto the second group of mobile devices that are outside the RF coverageboundary of WLAN 600. These indications may be additionally oralternatively viewed as indications corresponding to whether or not APtripwire coverage is desired or not desired. Through such associations,wireless AP 614 may be made aware which mobile devices should beincluded within the AP tripwire coverage.

The configuration procedure/adaptive beamforming technique of wirelessAP 614 may be initiated in response to a user interface signal from auser interface. During the configuration procedure, where wireless AP614 is operated in the configuration mode of operation, wireless AP 614receives RF signals from the first group of mobile devices 620, 622,624, 626, 632, and 680 and the second group of mobile devices 630, 634,636, 638, and 639. Such communications may be performed for a particularfrequency or frequency pair of the relevant RF band of interest for RFcommunications, or alternatively for two or more frequencies of the RFband in wideband environments (e.g. OFDM systems). RF signals receivedfrom each mobile device may include one or more messages which conveythe mobile device identifier of the mobile device to wireless AP 614.Some of these mobile devices also transmit and receive RF signals to andfrom other “interior” wireless APs (e.g. wireless APs 606 and 610) whentheir positioning allows for it.

While receiving RF signals from the mobile devices, wireless AP 614operates to automatically adjust and subsequently set boundaries of itsRF coverage region 616 so as to minimize RF signal coverage for firstgroup of mobile devices 620, 622, 624, 626, 632, and 680 but maximize RFsignal coverage for second group of mobile devices 630, 634, 636, 638,and 639. Wireless AP 614 determines which RF signals should be maximizedor minimized based on both the mobile device identifier associated withthe RF signal and the indication of whether the mobile device should bewithin or outside the AP tripwire coverage. More specifically, a minimaxoptimization technique may be utilized during the configurationprocedure. With use of the minimax optimization technique, RF signalsare minimized for those communication devices outside of the desired RFcoverage region and maximized for those communication devices within thedesired RF coverage region.

During the configuration procedure, wireless transceiver parametersassociated with wireless AP 614 are varied for each antenna element ofthe antenna array and subsequently set in place. Once obtained, theparameters are stored in memory of wireless AP 614 for its subsequentuse in the handoff indication mode of WLAN 600. See the previousdiscussion in relation to FIGS. 3 and 4. Again, in a widebandenvironment (e.g. OFDM systems) this procedure may be repeated formultiple frequency channels (e.g. each and every frequency channel)utilized between wireless AP 614 and mobile devices for RFcommunications, assuming there is some frequency dependence for RFcommunications in the relevant RF band of interest.

FIG. 8 shows a suitable RF coverage region 802 of wireless AP 614 as aresult of such transceiver parameter adjustment. As illustrated, theboundaries of RF coverage region 802 have been adjusted and set so as tominimize RF signal coverage for first group of mobile devices 620, 622,624, 626, 632, and 680 (locations of undesired AP tripwire coverage)while maximizing RF signal coverage for second group of mobile devices630, 634, 636, 638, and 639 (locations of desired AP tripwire coverage).In this example, wireless AP 614 now fails to provide adequate RFcoverage for mobile devices 620, 622, 624, 626, 632, and 680 whileadequately providing RF coverage for mobile devices 630, 634, 636, 638,and 639. RF coverage region 802 overlaps with a small portion of the RFcoverage region of WLAN 600 as well as a small portion of RF coverageregion 604 of the WWAN.

RF coverage region 802 shown in FIG. 8 is merely an example. Asapparent, it may be desirable that RF coverage region 802 extend outsidethe RF coverage region of WLAN 600 by some predetermined distance orarea. In this case, some of second group of mobile devices 630, 634,636, 638, and 639 may be alternatively designated as devices for whichRF coverage region 802 of wireless AP 614 should not be provided. Forexample, it may be desirable to designate mobile devices 630 and 634 inparticular as devices which should not be provided RF coverage bywireless AP 614. That is, mobile devices 636, 638, and 639 just outsidethe boundary of the RF coverage region of WLAN 600 may remain designatedas being part of the second group of mobile devices (i.e. AP tripwirecoverage desired), while mobile devices 630, and 634 far outside theboundary may be included as being part of the first group of mobiledevices (i.e. no AP tripwire coverage desired). More generally, mobiledevices located within a first distance inside and outside of the RFcoverage boundary of WLAN 600 may be included within the group of mobiledevices to be within the resulting RF coverage region of wireless AP614, but mobile devices located between the first distance and a seconddistance greater than the first distance inside and outside of the RFcoverage boundary of WLAN 600 may not be included within this group.Again, the mobile device identifiers stored in the memory of wireless AP614 are assigned or associated in advance as being part of either onegroup or another (e.g. the first or the second group) depending on thedesired configuration.

Note again that other adjacent interior wireless APs (e.g. wireless APs606 and 610) may be adapted similarly to configure and adjust boundariesof its associated RF coverage regions, so as to fill in resulting holesor gaps in RF coverage in response to the resulting RF coverage regionof wireless AP 614. This may be done in order to minimize false handoffsfor mobile devices.

FIG. 9 shows RF coverage region 802 of wireless AP 614 after theconfiguration procedure where the first and the second group of mobiledevices are removed and the wireless AP 614 may be utilized as thehandoff indication mechanism in WLAN 600. In one embodiment, RF coverageregion 802 of wireless AP 614 is set and remains fixed during operationof wireless AP 614 in the handoff indication mode. After theconfiguration procedure, and during steady-state operation of wirelessAP 614, wireless AP 614 operates in what is referred to as a “handoffindication” mode of operation. When a mobile device is within an RFcoverage region 802 of wireless AP 614, it is likely that the mobiledevice will be exiting or entering the RF coverage of WLAN 600. If themobile device is exiting WLAN 600, then it may need to be handed-off tothe WWAN in RF coverage area 604. Therefore, when the mobile device iswithin RF coverage region 802, wireless AP 614 causes a handoffindication to be sent to the mobile device, to WLAN 600, or to both, inorder to assist in providing a more reliable and timely vertical handofffor the mobile device to the WWAN. Since it has gone through aconfiguration procedure, wireless AP 614 has an RF coverage region 802that is suitably configured to reduce the likelihood that wireless AP614 will cause a handoff indication to be sent wrongfully (e.g. falsedetection) or prematurely. RF coverage region 802 is also suitablyconfigured so that wireless AP 614 will not cause the handoff indicationto be provided too late (i.e. after the handoff procedure has been orshould have been initiated) but rather indeed to serve the purpose ofproviding adequate forewarning.

In another embodiment of FIG. 9, RF coverage region 802 of wireless AP614 is initially set but may change from time to time duringsteady-state operation of wireless AP 614 in the handoff indicationmode. In particular, RF coverage region 802 may be automaticallyadjusted in response to feedback from WLAN 600. This feedback may be,for example, an indication of the success or failure rate of mobiledevice handoffs from the WLAN to the WWAN. In this case, RF coverageregion 802 may be adjusted so as to expand outwards from the RF coverageboundary of WLAN 600 to increase the success rate of mobile devicehandoffs. The feedback may also be an indication of false detect rateswhere RF coverage region 802 may be adjusted to provide less overlapwith RF coverage of WLAN 600. As another example, the feedback may be anindication that the RF coverage boundary of WLAN 600 has been changed.In this case, boundaries of RF coverage region 802 of wireless AP 614may be adjusted in accordance with the change in the RF coverageboundary of WLAN 600.

Referring now back to FIG. 5, a flowchart of a method of configuring thewireless AP for use as the handoff indication mechanism in the WLAN isshown. The following description of FIG. 5 relates to the description ofFIGS. 6-9 above. The method of FIG. 5 may be embodied at least in partas a computer program product which includes a computer readable mediumand computer instructions stored in the computer readable medium whichare executable by one or more processors of the wireless AP forperforming the method. After its initiation, the technique is performedautomatically by the one or more processors without further userintervention. After the configuration procedure, the wireless APoperates with use of configured wireless transceiver parameters in anormal, steady-state mode of operation as the AP tripwire of the WLAN.

Beginning at a start block 502 of FIG. 5, a plurality of communicationdevices for the configuration procedure are provided and fixedlypositioned around the ingress/egress region of the WLAN (step 504 ofFIG. 5). As described earlier above, in one approach, the communicationdevices are mobile devices which have the same or similar structure andfunctionality as mobile terminal 138 of FIG. 2 and are operational forend users as ordinary mobile communication devices. In another approach,the communication devices are specially-designed configuration deviceswhich are not operational for end users as ordinary mobile communicationdevices. In the present example, the communication devices are mobiledevices.

In step 504, a first group of mobile devices are positioned at locationsof undesired RF coverage for the AP tripwire, outside of an RF coverageboundary of a WLAN coverage region of one or more other wireless accesspoints of the WLAN. On the other hand, a second group of mobile devicesare positioned at locations of desired RF coverage for the AP tripwire,around the RF coverage boundary of the WLAN coverage region as well aswithin the WWAN coverage region. See the previous description inrelation to FIG. 7. The positioning of the mobile devices is performedby one or more individuals, with or without the assistance of any otherWLAN feedback signal mechanisms if necessary.

After mobile device positioning, radio frequency (RF) signals from themobile devices are received by the wireless AP (step 506 of FIG. 5).Such communications may be performed for a particular frequency orfrequency pair of the relevant RF band of interest for RFcommunications, and alternatively for two or more frequencies of the RFband in wideband environments (e.g. OFDM systems). Note also that someof the mobile devices also receive RF signals to and from other“interior” wireless APs (e.g. wireless APs 606 and 610) when theirpositioning allows for it.

Next, an RF signal coverage region of the wireless AP is automaticallyadjusted and set based on the RF signals using an adaptive beamformingtechnique, and preferably based on a minimax optimization (step 508 ofFIG. 5). Specifically, transceiver parameters of the wirelesstransceiver array of the wireless AP are adjusted and set such that RFsignal coverage of the first group of mobile devices is minimized(locations of undesired AP tripwire coverage) but RF signal coverage ofthe second group of mobile devices is maximized (locations of desired APtripwire coverage) (step 510 of FIG. 5).

The RF signals from each mobile device may include a mobile deviceidentifier which uniquely identifies the mobile device, amongst otherdata. Mobile device identifiers may also be stored in memory of thewireless AP, and assigned or associated in advance with an indicationcorresponding to either one group (e.g. desired AP tripwire coverage) oranother group (e.g. no desired AP tripwire coverage). The wireless APmay determine which RF signals should be maximized or minimized based onthe mobile device identifier associated with the RF signal and theindication (received and/or stored in memory) of whether the mobiledevice should or should not be within the AP tripwire coverage.

Once the transceiver parameters are obtained, they are stored in memoryfor use by the wireless AP tripwire (step 512 of FIG. 5). Again, thisprocedure may be performed once for a particular frequency of the RFband of interest for some systems, or alternatively may be repeated formultiple frequency channels (e.g. each and every frequency channel)utilized between the wireless AP and mobile devices, assuming somefrequency dependence on the communication of RF signals in the relevantRF band of interest.

Thus, methods and apparatus for use in configuring a wireless accesspoint (AP) which serves as a handoff indication mechanism (“APtripwire”) in a wireless local area network (WLAN) for mobile devicehandoffs between the WLAN and a wireless wide area network (WWAN) havebeen described. During a configuration procedure for the wireless AP,radio frequency (RF) signals transmitted from a plurality ofcommunication devices are received by the wireless AP. The plurality ofcommunication devices includes a first group of communication devicespositioned at locations of undesired RF coverage outside of an RFcoverage boundary of a WLAN coverage region of one or more otherwireless APs of the WLAN, as well as a second group of communicationdevices positioned at locations of desired RF coverage around the RFcoverage boundary of the WLAN coverage region and within the WWANcoverage region. Based on the received RF signals, wireless transceiverparameters of the wireless AP are automatically determined and set toadjust boundaries of an RF coverage region of the wireless AP, such thatRF signal coverage of the first group of communication devices isminimized but RF signal coverage of the second group of communicationdevices is maximized. Preferably, the wireless transceiver parametersare determined and set through use of an adaptive beamforming technique(e.g. a minimax optimization) which is performed automatically by thewireless AP during the configuration procedure without userintervention. After the configuration procedure, the wireless APoperates with use of the configured wireless transceiver parameters in anormal, steady-state mode of operation as the AP tripwire of the WLAN.Advantageously, the RF signal coverage of the AP tripwire isappropriately adjusted and set so as to help provide reliable and timelymobile device handoffs between the WLAN and the WWAN.

A wireless access point of the present disclosure includes an antennaarray, a wireless transceiver array coupled to the antenna array, andone or more processors which are coupled to the wireless transceiverarray. The one or more processors are adapted to operate in a handoffindication mode in a wireless local area network (WLAN) for mobiledevice handoff between the WLAN and a wireless wide area network (WWAN).The one or more processors are further adapted to operate in aconfiguration mode to receive, by the wireless transceiver array, radiofrequency (RF) signals from a plurality of communication devices, and tosubsequently adjust and set wireless transceiver parameters of thewireless transceiver array for adjusting boundaries of an RF coverageregion of the wireless access point. The plurality of communicationdevices include a first group of communication devices positioned atlocations of undesired RF coverage outside of an RF coverage boundary ofa WLAN coverage region of one or more other wireless access points ofthe WLAN. The plurality of communication devices also include a secondgroup of communication devices positioned at locations of desired RFcoverage around the RF coverage boundary of the WLAN coverage region andwithin the WWAN coverage region. The parameters of the wirelesstransceiver are determined and set so that RF signal coverage of thefirst group of communication devices is minimized but RF signal coverageof the second group of communication devices is maximized.

A wireless local area network (WLAN) of the present disclosure includesa plurality of wireless access points which define a WLAN radiofrequency (RF) coverage region for wireless communications in the WLAN.The WLAN further includes a unique wireless access point which isoperative to serve as a handoff indication mechanism in the WLAN formobile device handoff between the WLAN and a wireless wide area network(WWAN). The wireless access point includes an antenna array, a wirelesstransceiver array coupled to the antenna array, and one or moreprocessors which are coupled to the wireless transceiver array. The oneor more processors are adapted to operate in a handoff indication modein the WLAN for mobile device handoff between the WLAN and the WWAN. Theone or more processors are further adapted to operate in a configurationmode to receive, by the wireless transceiver array, RF signals from aplurality of communication devices, and to subsequently adjust and setparameters of the wireless transceiver array for adjusting boundaries ofan RF coverage region of the wireless access point. The plurality ofcommunication devices include a first group of communication devicespositioned at locations of undesired RF coverage outside of an RFcoverage boundary of a WLAN coverage region of one or more otherwireless access points of the WLAN. The plurality of communicationdevices also include a second group of communication devices positionedat locations of desired RF coverage around the RF Coverage boundary ofthe WLAN coverage region and within the WWAN coverage region. Theparameters of the wireless transceiver array are determined and set sothat RF signal coverage of the first group of communication devices ismaximized but RF signal coverage of the second group of communicationdevices is minimized.

The above-described embodiments of the present disclosure are intendedto be examples only. In the present disclosure, the examples describedwere directed to WLANs of the IEEE 802.11 network type and WWANs of thecellular network type. However, the WLAN and WWANs may be any suitableheterogeneous networks. For example, one of the networks may be a WiMAX(e.g. 802.16-based) network. If the WLAN is a WiMAX network, forexample, then the WWAN may be a cellular telecommunications network.Also for example, if the WWAN is a WiMAX network, then the WLAN may bean IEEE 802.11-based network. Those of skill in the art may effectalterations, modifications and variations to the embodiments withoutdeparting from the scope of the application.

What is claimed is:
 1. A method for use in operating a wireless accesspoint for serving as a handoff indication mechanism in a first wirelessnetwork, the handoff indication mechanism being configured tocommunicate handoff indications in response to mobile communicationdevices leaving coverage of the first wireless network, via a radiofrequency (RF) coverage region of the wireless access point, for mobiledevice handoff to a second wireless network, the method comprising:providing the wireless access point in an ingress or egress region ofthe first wireless network; receiving, by the wireless access point, RFsignals from one or more communication devices, and determining andsetting wireless transceiver parameters of the wireless access point foradjusting boundaries of the RF coverage region of the wireless accesspoint; and operating the wireless access point with the adjusted RFcoverage region to serve as part of the handoff indication mechanism inthe first wireless network, so that the handoff indications arecommunicated in response to the mobile communication devices leavingcoverage of the first wireless network, via the adjusted RF coverageregion, for mobile device handoff to the second wireless network.
 2. Themethod of claim 1, wherein the first wireless network comprises awireless local area network (WLAN) and the second wireless networkcomprises a wireless wide area network (WWAN).
 3. The method of claim 1,wherein the wireless access point is operative in accordance with anIEEE 802.11-based standard or an IEEE 802.16-based standard.
 4. Themethod of claim 1, wherein the second wireless network comprises acellular telecommunications network.
 5. The method of claim 1, whereinthe acts of determining and setting the wireless transceiver parametersof the wireless access point comprise an adaptive beamforming technique.6. The method of claim 1, wherein the acts of determining and settingthe wireless transceiver parameters comprise a minimax optimizationtechnique.
 7. The method of claim 1, wherein the acts of receiving theRF signals from the one or more communication devices and determiningand setting the wireless transceiver parameters are performed during aconfiguration procedure of the wireless access point.
 8. The method ofclaim 2, further comprising: providing the wireless access point withthe adjusted RF coverage region to serve as part of the handoffindication mechanism in the WLAN by: identifying whether a mobilecommunication device is within the adjusted RF coverage region of thewireless access point; and causing a handoff indication to be sent to atleast one of the mobile communication device and the WLAN when themobile device is identified to be within the adjusted RF coverage regionof the wireless access point.
 9. The method of claim 2, wherein the oneor more communication devices include communication devices positionedat locations of desired RF coverage around the RF coverage boundary ofthe WLAN coverage region, and wherein the acts of determining andsetting wireless transceiver parameters are performed such that RFsignal coverage of the one or more communication devices is maximized.10. The method of claim 2, wherein the one or more communication devicesinclude a first group and a second group of communication devices, thefirst group of communication devices being positioned at locations ofundesired RF coverage around an RF coverage boundary of the WLANcoverage region, the second group of communication devices beingpositioned at locations of desired RF coverage around the RF coverageboundary of the WLAN coverage region, and wherein the acts ofdetermining and setting wireless transceiver parameters of the wirelessaccess point are performed such that RF signal coverage of the firstgroup of communication devices is minimized but RF signal coverage ofthe second group of communication devices is maximized.
 11. A wirelessaccess point which is configured for use in an ingress or egress regionof a wireless network, the wireless access point comprising: an antennaarray; a wireless transceiver array coupled to the antenna array; one ormore processors which are coupled to the wireless transceiver array; theone or more processors being configured to: receive, by the wirelesstransceiver array, RF signals from one or more communication devices;determine and set wireless transceiver parameters of the wirelesstransceiver array for adjusting boundaries of an RF coverage region ofthe wireless access point based on the RF signals; and the one or moreprocessors being further configured to operate the wireless access pointin a handoff indication mode, with the adjusted RF coverage region, forcausing handoff indications to be communicated in response to mobilecommunication devices leaving coverage of the wireless network, via theadjusted RF coverage region, for mobile device handoff to an alternativewireless network.
 12. The wireless access point of claim 11, wherein thefirst wireless network comprises a wireless local area network (WLAN)and the second wireless network comprises a wireless wide area network(WWAN).
 13. The wireless access point of claim 11, wherein the wirelessaccess point is operative in accordance with an IEEE 802.11-basedstandard or an IEEE 802.16-based standard.
 14. The wireless access pointof claim 11, wherein the one or more processors are configured todetermine and set the wireless transceiver parameters based on anadaptive beamforming technique.
 15. The wireless access point of claim11, wherein the one or more processors are configured to determine andset the wireless transceiver parameters based on a minimax optimizationtechnique.
 16. The wireless access point of claim 12, wherein the one ormore communication devices include communication devices positioned atlocations of desired RF coverage around the RF coverage boundary of theWLAN coverage region, and wherein the one or more processors are furtherconfigured to determine and set the wireless transceiver parameters ofthe wireless transceiver array for adjusting boundaries of the RFcoverage region such that RF signal coverage of the communicationdevices is maximized.
 17. The wireless access point of claim 11, whereinthe one or more communication devices comprise mobile communicationdevices.
 18. A wireless communication network, comprising: a pluralityof wireless access points which define a coverage for wirelesscommunications in the wireless network; a wireless access point which isprovided in an ingress or egress region of the wireless network; thewireless access point being operative to serve as a handoff indicationmechanism in the wireless network for causing handoff indications to becommunicated in response to mobile communication devices leavingcoverage of the wireless network, via a radio frequency (RF) coverageregion of the wireless access point, for handoff to an alternativewireless network; the wireless access point having: an antenna array; awireless transceiver array coupled to the antenna array, the wirelesstransceiver array being operative for RF communications with use oftransceiver parameters; one or more processors which are coupled to thewireless transceiver array; the one or more processors being configuredto: receive, by the wireless transceiver array, RF signals from one ormore communication devices; and determine and set the transceiverparameters of the wireless transceiver array for adjusting boundaries ofthe RF coverage region of the wireless access point based on the RFsignals, to produce an adjusted RF coverage region of the wirelessaccess point for operation in the handoff indication mode.
 19. Thewireless network of claim 18, wherein the first wireless networkcomprises a wireless local area network (WLAN) and the second wirelessnetwork comprises a wireless wide area network (WWAN).
 20. The wirelessnetwork of claim 18, wherein the wireless access point is operative inaccordance with an IEEE 802.11-based standard or an IEEE 802.16-basedstandard.
 21. The wireless network of claim 18, wherein the one or moreprocessors are further configured to determine and set the transceiverparameters based on an adaptive beamforming technique.
 22. The wirelessnetwork of claim 18, wherein the one or more processors are furtherconfigured to determine and set the transceiver parameters based on aminimax optimization technique.
 23. The wireless network of claim 19,wherein the one or more communication devices include communicationdevices positioned at locations of desired RF coverage around the RFcoverage boundary of the WLAN coverage region, and the one or moreprocessors are further configured to operate in a configuration mode to:determine and set wireless transceiver parameters such that RF signalcoverage of the one or more communication devices is maximized.
 24. Thewireless network of claim 19, wherein the one or more communicationdevices include a first group and a second group of communicationdevices, the first group of communication devices being positioned atlocations of undesired RF coverage around an RF coverage boundary of theWLAN coverage region, the second group of communication devices beingpositioned at locations of desired RF coverage around the RF coverageboundary of the WLAN coverage region, and the one or more processors arefurther configured to operate in the configuration mode to: determineand set wireless transceiver parameters of the wireless access pointsuch that RF signal coverage of the first group of communication devicesis minimized but RF signal coverage of the second group of communicationdevices is maximized.